Turbo-pump unit for extinguishing fires



June 8, 1937. l A. LAMERE 2,083,167

TURBO-PUMP UNIT FOR EXTINGUISHING FIRES I Filed Deo. 24, 1935 Egal. L i

Patented June 8, 1937 UNITED STATES PATENT OFFICE Andr Lamre, Paris,France, assigner to vSocit de Moteurs Gaz et dlndustrie Mecanique,Paris, France, a company of France .Application December 24, 193s, semiNo. sans In France December 27, 1934 (Cl. 10d-87 The present inventionrelates to improvements the form of an inverted Y in the leg of which inmotor-pump units intended for extinguishing fires by projecting upon theseat of the fire a chemical foam formed at the moment of use by theunion in a common delivery conduit of two Asolutions which cause theformation of the said foam 'when mixed together, the said solutionsbeing supplied. by two separate conduits fed respectively by two pumpsdriven by 'a motor common to both.

In the motor-pump unit according to the invention, the two pumps eachforcing one of the two solutions respectively 'are centrifugal pumpsdriven by the same hydraulic turbine mounted on the shaft common to thetwo pumps and between the latter, the two wheels of the pumps and thewheel of the turbine being moreover disposed in a common casing framecarrying the suction and delivery connecting pieces necessary for thepumps, as well as the admission and outlet connecting pieces for theturbine. The device furthermore comprises means for preventing, withoutthe use of a stuffing box, any mixing of the solutions in the interiorof the casing. Thereis thus provided a compact and perfectly balancedconstruction, which is easy to keep in repair and ensures anirreproachable operation of the turbopump unit. 4

' In the accompanying drawing showing by way of example a-form ofconstruction of the invention, Figure 1 is a sectional elevation on theaxis of the shaft common to the pumps and turbine.y

Figure 2 is a cross-section of the turbine on the line II-II of Figure 1and Figure 3 is acrosssection of one of the pumps on the line III-IlI ofthe same Figure 1.-

'Ihe turbine comprises a blade wheel or impeller I mounted on a shaft 2and rotating in a central chamber a of a. casing frame 3 common to theturbine and to the pumps. The water under pressure enters through thedistributor or guide ring 4, passes through the blade wheel I in thedirections shown by the arrows, and leaves by the connecting piece 5.

Two centrifugal pump discs 6 and 1 are mounted on the ends of the shaft2 suitably extended for that purpose, and rotate in the same casingframe 3', in which are provided the two end chambers b, b. The disc 5draws one of the solutions through the conduit 8 and the disc I drawsthe other solution. through the conduit 9. The solutions are deliveredinto diiusers Il and Il, provided in the end chambers -of the saidcasing frame 3. The outlets l2 and I3 of these diifusers are connectedby a header I5 having the mixing of the two liquids takes place. Theresulting emulsion leaves by I6 to be directed towards the nozzle of thenre hose.

In order to prevent the elementary solutions from passing through thebearings I1 and i8 provided in the frame for the shaft 2 and mixing inthe turbine, a partial vacuum is created in the f said bearings byutilizing for this purpose the known means for reducing leakage betweenthe discs of the pump and the casing. The discs the vicinity of thebearings I1 and I8, it is greater than the suction pressure of the discs5 and 1, for example by creating a sumcient loss of head at the outlet 5of the turbine. Under these conditions, leakage occurs from 25 towards y23 and from 25 towards 24 but not in the opposite direction.

I claim:

1. A turbo-pump unitzof the type adapted to separately deliver twodifferent water-miscible liquids to a common mixing chamber and deliveryconduit, comprising a common casing for housing all of the elements ofsaid unit, a pair of pump chambers disposed within said casing at theopposite ends thereof, -a turbine chamber disposed within said casingbetween said pump chambers, l

a hydraulically operatedturbine in said turbine chamber, a shaft forsaidturbine, packless bearings for said shaft in the walls of said casingbetween said turbine chamber and said lpump chambers'. the ends of saidshaft extending through said walls and into said pump chambers,centrifugal pump impellers mounted in said pump chambers on the ends ofsaid shaft, separate inlets to said pump chambers vcoaxial withsaidshaft for supplying the water-miscible liquids thereto, separate outletsfrom said pump chambers joining inra common mixing chamberP-a separateinlet and outlet fo'rsaid turbine chamber,

`saidturbine outlet being in direct communication with the inner ends ofsaid packless bearings and so constructed and arranged that the pressureof the water discharged therefrom exceeds the suction pressure of eachof said pumps, and means for establishing communication between theouter ends of said bearings and the suction sides of said pumpimpellers, whereby a' pressure differential is created that i'orces'anyleakage through said bearings to iiow from said turbine chamber to saidpump chambers and prevents any passage of the water-miscible liquidsinto the turbine chamber.

2.*A reghting, turbo-pump unit of the type adapted to separatelydelivertwo dierent watermiscible` liquids to a common mixing chamber anddelivery conduit wherein their mixture producesa ire extinguishing foam,comprising a common 'casing for housing all of the elements of saidunit, a pair of pump chambers disposed within said casing at theopposite ends thereof, a-turbine chamber disposed within said casingVbetweensaidpump chambers, a' hydraulically operated turbine in saidturbinechamber. a shaft for said turbine, packless bearings for saidshaft in the walls of said casing between said turbine chamber and saidpump chambers, the ends of said shaft extending through said walls andinto said pump chambers, centrifugal pump impellers said shaft, separateinlets to said pump'chambers coaxial with said shaft for supplying thewatermiscible, foam-producing liquids thereto, separate outlets fromsaid pump chambers joining in a common mixing chamber, a separate inletand outlet for said turbine chamber, said turbine outlet being indirectcommunication with the inner ends of said packless bearings and soconstructed and arranged that the pressure of the water dischargedtherefrom exceeds the` suction pressure of each of said pumps, leakagereceiving pockets formed between said pump impellers and the adjacentwalls of said casingand in direct communication with the outer ends ofsaid bearings, and vopenings in said impellers providing communicationbetween said pockets and the suction sides of said impellers, whereby lapressure difierential is created that forces any leakage through saidbearings to flow from said turbine chamber to said pump chambers andprevents any pasf sage of the foam-producing liquids into the turbinechamber.

ANDR LAMRE.

Cil

